Frank Mankiewicz, the press secretary who went before television cameras to announce the death of Sen. Robert F. Kennedy and later served as political director for presidential candidate George McGovern, died Thursday. He was 90.

Mankiewicz died of a heart attack at George Washington University Hospital, said a family friend, journalist Adam Clymer.

Mankiewicz was a longtime Democratic political operative as well as a lawyer, journalist and author. McGovern once recalled his former campaign aide as a perceptive, straightforward political adviser.

"I never got any bad advice from Frank," said McGovern, a senator from South Dakota who was the Democratic nominee for president in 1972. "I found him just fascinating to travel with during the campaign. I picked up a lot of perspective, a lot of insights and a lot of humor from Frank."

The son and nephew of Hollywood filmmakers, Mankiewicz studied journalism and law. He worked for newspapers in Washington, D.C., and Los Angeles before assuming the role of President John F. Kennedy's Peace Corps director in Lima, Peru, in 1962 and later was a regional director in Washington. In 1966, he became press secretary to Sen. Robert Kennedy, D-N.Y., who was assassinated two years later while campaigning for the party's presidential nomination.

In June 1968, Kennedy had just won the California primary and finished his victory speech at the Ambassador Hotel in Los Angeles. Mankiewicz left the entourage for a moment to help the candidate's wife, Ethel, step off a platform.

"She was at the time three months pregnant, although I don't think anybody knew it, except the inside group," Mankiewicz recalled on the 30th anniversary of Kennedy's assassination. "We helped her down. And then she said, 'Go on,' and we started to move off quickly to catch up. And that's when we heard the shots."

Kennedy was gunned down in a kitchen pantry by Sirhan Sirhan, a young Palestinian later convicted of his murder. Mankiewicz issued medical bulletins throughout the day as Kennedy lingered near death at The Good Samaritan Hospital. Some 26 hours later, Mankiewicz emerged, pale and haggard but poised, to deliver tragic news.

"I have a short announcement to read which I will read at this time. Sen. Robert Francis Kennedy died at 1:44 a.m. today, June 6, 1968. ... He was 42 years old," Mankiewicz said.

He would later recall: "That, in many ways, was the shaping influence in my adult life."

Mankiewicz went to work for McGovern in 1971, reflecting some time afterward that he "thought McGovern had the right issues, and history has tended to bear him out."

An outspoken critic of Richard Nixon, Mankiewicz wrote two books about the disgraced president: "Perfectly Clear: Nixon From Whittier to Watergate" and "U.S. v. Richard M. Nixon: The Final Crisis." He was delighted when Nixon resigned.

"I think we should celebrate Aug. 9 as a day of national liberation every year," he told the Philadelphia Bulletin. "Every country celebrates the day the government got rid of its tyrants. We should too."

After McGovern's decisive defeat, Mankiewicz wrote a column for The Washington Post and in 1976 made an unsuccessful bid for the Democratic nomination for a House seat from Maryland. He was named president of National Public Radio in 1977 and was credited with strengthening its news operation and doubling its audience. He resigned in 1983 as NPR faced a multimillion-dollar budget deficit and then joined the public relations firm of Gray & Co., which eventually became Hill & Knowlton.

Born on May 16, 1924, Mankiewicz grew up in Beverly Hills, California, among a family of notables. His father, Herman J. Mankiewicz, was a screenwriter who won an Oscar for co-writing the landmark film "Citizen Kane." His uncle, Joseph L. Mankiewicz, won four Oscars for writing and directing "A Letter to Three Wives" and "All About Eve."

Frank Mankiewicz served in the Army during the latter part of World War II. He received a bachelor's degree from the University of California, Los Angeles, in 1947, followed by a master's in journalism from Columbia University and a law degree from the University of California, Berkeley.

Frank Mankiewicz, the press secretary who went before television cameras to announce the death of Sen. Robert F. Kennedy and later served as political director for presidential candidate George McGovern, died Thursday. He was 90.